Car Ran Out of Diesel and Now it wont start - Page 2 - PeachParts Mercedes-Benz Forum

TMAllison · #16 10-22-2007, 11:44 PM

An yet, he hasnt even tried using it and thats what it there for, to manually pump fuel up to the inj's.

Not using it first is foolish. Cracking lines and cranking the starter is the second step in the process.

*edit* To clarify, cracking a hard line and cranking is the third step. Cracking a hard line and manually pumping the primer is the second step.

BoomInTheTrunk · #17 10-22-2007, 11:46 PM

i have fuel to the pump and filters just not sure if the fuel is getting to the injectors. again just how hard is it to remove the line from the injector i was having trouble and didn't want to force it. also when i used the pump, fuel was coming out the sides of it is this normal or is it bad.

TMAllison · #18 10-23-2007, 12:11 AM

So you did pump it and yes, that is bad. You have a bad seal where it is leaking and it is allowing air to enter the system.

It sounds like you need a new manual pump.

This is what a new style pump looks like, if yours is white and you have to unscrew it before using it then it is OEM and 26 years old.

http://catalog.worldpac.com/mercedesshop/sophio/image.jsp?title=Primer%20Pump&url=http%3A//img.eautopartscatalog.com/live/D2010268357BOS.JPG

BoomInTheTrunk · #19 10-23-2007, 12:17 AM

yah mine is the old style, can the new style be used in its place or do i have to buy another old style. also were can i get the new style and for about how much.

Mustang_man298 · #20 10-23-2007, 12:27 AM

You can use the newer style on yours, both styles are still available. They are plentiful out on fleapay or you can get them here on the site too I'm sure. Theyre pretty cheap, I think around $25 or so if I remember right.....
Your lines should be firmly tightened on the injectors, and may be even more so if they've not been disturnbed for many years. You might have to give the wrench a sharp whack to break them loose if they're really stuck. I'd pop all of them @ the injectors and keep cranking (in 30 sec bursts) until fuel comes out of at least one. It does take a while even if you've gotten fuel to the IP.

Someone mentioned running the engine on WD40 in a different thread for testing an engine...perhaps you could try starting it with a few spritzes and keep spraying enough at it to keep it going until it picks up the fuel.

BoomInTheTrunk · #21 10-23-2007, 01:07 AM

is this the newer style pump
http://www.***************/search/product.aspx?gkw=Mercedes+300DT+Diesel+Primer+Pump&gad=CKP7wboDEgjuUnZinSjHGBjtn_T8AyCjxe8p&makeid=800016@Mercedes&modelid=1193767@300DT&year=1982&cid=22@Fuel%20%26%20Air%20System&gid=6259@Diesel%20Primer%20Pump
the second one

Bill Ladd · #22 10-23-2007, 08:10 AM

Quote:

Originally Posted by BoomInTheTrunk

is this the newer style pump
http://www.***************/search/product.aspx?gkw=Mercedes+300DT+Diesel+Primer+Pump&gad=CKP7wboDEgjuUnZinSjHGBjtn_T8AyCjxe8p&makeid=800016@Mercedes&modelid=1193767@300DT&year=1982&cid=22@Fuel%20%26%20Air%20System&gid=6259@Diesel%20Primer%20Pump
the second one

Yes, the second one.

winmutt · #23 10-23-2007, 08:41 AM

Quote:

Originally Posted by TMAllison

Cracking a hard line and manually pumping the primer is the second step.

May very well do nothing.

TMAllison · #24 10-23-2007, 12:58 PM

Quote:

Originally Posted by winmutt

May very well do nothing.

I guess my expiriences are very different from everyone else's.

I just did this Sunday on my 85 as the city made me move it. It had sat for 6 months missing #1 & #2 injectors (long term loan to board member "Frankie" back in April when her #5 cyl bit the big one from SVO use). Fuel system was open and prime was lost; additionally the battery was very weak and was parked nose uphill. Installed the injectors, reconnected hard lines and return lines, pumped "new style" primer pump 25 times and had fuel leaking out of first three inj return lines making a mess. Obviously, fuel was pumped up to the inj's and inside them to cause the return lines to begin leaking.

Battery was only strong enough to turn engine over once. It coughed. Waited a few minutes, glowed twice, turned key and got a half turn on the engine and it fired up, spluttered for a second and then ran smooth.

Brian Carlton · #25 10-23-2007, 01:31 PM

Quote:

Originally Posted by TMAllison

I guess my expiriences are very different from everyone else's.

I just did this Sunday on my 85 as the city made me move it. It had sat for 6 months missing #1 & #2 injectors (long term loan to board member "Frankie" back in April when her #5 cyl bit the big one from SVO use). Fuel system was open and prime was lost; additionally the battery was very weak and was parked nose uphill. Installed the injectors, reconnected hard lines and return lines, pumped "new style" primer pump 25 times and had fuel leaking out of first three inj return lines making a mess. Obviously, fuel was pumped up to the inj's and inside them to cause the return lines to begin leaking.

Battery was only strong enough to turn engine over once. It coughed. Waited a few minutes, glowed twice, turned key and got a half turn on the engine and it fired up, spluttered for a second and then ran smooth.

This is rather interesting, Terry.

I was always of the assumption that the low pressure side of the IP could not effect the high pressure side in any way. In theory, you could pressurize the low side to 20 psi with a pump and the fuel would not pass through the elements.

But, clearly, in your situation, the small pressure developed by the primer pump was sufficient to fill the IP and send fuel through the elements to the injectors..........something that I would have thought to be impossible.

Might have to do a test on the SD with the fuel lines disconnected.........

winmutt · #26 10-23-2007, 01:52 PM

Quote:

Originally Posted by Brian Carlton

But, clearly, in your situation, the small pressure developed by the primer pump was sufficient to fill the IP and send fuel through the elements to the injectors..........something that I would have thought to be impossible.

This was more to my point. If he cracked #5 (one injector) and hand pumped and it came out he got lucky that the engine was in the right place, delivery valves open etc.

TMAllison · #27 10-23-2007, 02:00 PM

Perhaps I was fortunate with the timing? I had not cranked it at all prior to installing the missing inj's so would assume #3-5 were still primed. #1 & 2 inj's and hard lines def wern't although the IP would have been. When using the primer pump the return lines began weeping in order from front to back.